Tractor



E. E. LARSON.

TRACTOR. APPLICATION FILED MAR. 9, I9I8. RENEWED APR. 30. 1920.4

Patented Sept. 7, 1920.,

3 SHEETS-SHEET 2.

gEn E. LARSON.

TRACTOR. APPLICATION FILED MAR. 9. Isla. IIENEwEn APII. 3o. i920'.

UNITED STATES mrisivi OFFICE.

EDWARD EfLARsoN, or. THOMPSON, IOWA. 1

TRACTOR. n

Application led March `9, 1,9178, Serial` 110.221,490. Renewed Apri1 30, 1920. Serialv No. 378,015.

To all whom t may concern.'

Be itknown that I, EDWARD E. LARsoN, v

a citizen of the United States, residing at Thompson, in the county of 7Winnebago' and.

State of Iowa, have invented a new and Improved Tractor, of which the following is a full, clear, and exact description. I

My invention relates to tractors and. an

obj ect thereof is to provide a simple and ef-A iicient tractor characterized .by propelling.

membersof the walking type.

Vith the'above and other objects in view,

tion and arrangement of parts 'as herein fully described, illustrated and claimed.

1n the accompanying drawings, forming part of the application, similar characters of reference indicate correspondingparts in all the views.

Figure .1 is a vertical section through a tractor frame on line 1-'-1, Fig. 2, the main parts of the tractor being shown in elevathe same directionl as the sprockets 16 the Y speeds of said sprockets 16 are greater than tion;

Fig. 2 is a plan of the tractor;l Fig. 3 is a section on line 3-3, Fig. 2; Fig. 4 is a section on line 4&4, Fig. 1; Fig. 5 is a section on line 5-5, Fig. 3; Fig. 6 is an elevation ofa shoe-carrying pinion; and y Fig. Y is a fragmentary elevation of the chain from which the shoe vis suspended.

Referring to the drawings, 8 is a rigid frame having in front an axle 9 which car" ries a pair of wheels 10 operable by a steering mechanism 11 afragmeiit only of which is shown in the drawings. 1n the rear the frame carries a pair of shoes 12, the vshoes`v bei-ng disposed on the opposite sides `of the central longitudinal plane ofthe frame.V

Each of the shoes isV suspended from .a lcorrespon-ding carriage 13 'mounted to roll on corresponding tracks 14 carried by the' frame.y Each Vof the carriages 13 vis constrained to travel with the links of 'a corresponding endless chain 15, the chainsfene gaging corresponding sprockets 16 and-17 i Specification of Letters Patent. E i Patnted Spgll,

the pinionsof the-.two differentials. Each i of the differentials is coupled byl an endless chain 23 to a corresponding sprocket 24.

. ently of one another and each carries a` pinion'26 in mesh with a corresponding rack 2'( carried by a beam 28 extending from the shoe 12 aliniiig with the corresponding pinion 26, the beam being rigidlyl connected to the shoe. To facilitate the movement of the beam by the shaft 25,-the same is provided i with rollers 29 which form roller bearings for the portion of `the' beam 28 which is below the Qrack.Y

As the motor 19 rotates the sprockets 16 in the direction indicatedl by the arrows, a track 14 is caused, to travel on a carriage 13, whereby the frame 8'is caused to move in the directiony indicated by the arrow in Fig. 1. The'movement of the tracks on the carriages imparts a rotary' movement to thev shafts 25 through the medium ofthe racks and when Vthe shafts 25 are rotated in if the shafts 25 were rotated in the opposite direction. When the shafts 25 rotate inthe direction opposite to the sprocket 16 the housing of the diiferentials'willalso rotate in the opposite direction to the sprocket's 16. The gearing of the differentials decreases the speed of the sprockets-16-when the differential housings rotate in a direc'- tion opposite to the sprockets, consequently `thespeed of the chain 10 will be greater when the? carriage 'is on the upper part of the tracks 14.V The differential mechanism,

therefore, carriesthe shoe not under .loadata greater speed than the frame moves onv the carriage; andit'fwill begseen that. the

. speed-must be' slightlyV more than .that of theffframe'gso/that a shoe'moving fromthe inoperativefto the voperative position will be lin time "to `engagethe lower face ofthe traekb'efore the-shoeI that is-Vat theend of,v its operative position-begins to roll vvoff thev ico that the shoes l2 may be considered-as supports on which the frame travels. The shoes are like Walking means which are successively placed into operative position so that the frame can slide thereon, the differential serving to move a support quickly during its inoperative position to bring it in time into operative position with reference to the frame to support the frame as the fra-me begins to leave the other support, ythat is, as the other support is rendered inoperative. It is self-evident that the form of the shoes may bevaried according to the ground in which theftractor Yis to be used.

While I have described the principle of operation, together With the device which I now consider to be the best embodiment vof the tracks, means for moving the carriages and the tracks relative toy one another, a shoe associated with each of the-v carriages, and means associated With the shoe for accelerating themovement of the carriage When the shoe is moved from the inoperative into the operative position.

2. A tractor comprising a frame, rolling means supporting oneV end of the frame, supports for the other end of the frame,

ltracks for said supports, means for moving the tracks and supports relative to one anotherwhereby the frame is -moved on the supports, and means for moving the supports on the tracks at a greater speed than .the frame moves, whereby a support can be moved quicker from the inoperative to v the operative position than from the operameans supporting one end of the frame,y

tive to lthe inoperative position.

3. A tractorV comprising a frame', `rolling supports for the yother end of the frame, a

roller bearing` interposed between the supports and the frame, endless tracks for said rolling means of the' supports, means for ymoving said frame and supports relative to one another, and'means associated With said moving means for increasing the relative lspeeds of said lframe and supports When said supports and frame are moved in the same direction.

4. A tractor comprising va frame, rolling lmeans supporting one end of the frame, supports for the other end of the frame, means shoes for the other end of the frame, a carriage associated With each shoe, an endless track on the frame for each of the carriages,V

an endless chain mounted to revolve about each track and connected to the carriage on the track, means for imparting rotary motion to the .endless chains, differentialsI interposed between the endless chains and the motion-imparting means, and means for revolving vthe differential housings operable by the shoes.

6. A tractor comprising a frame, Wheels supporting` the front of the frame, shoes for the rear of the frame, a carriage associated with each shoe, an endless track for each of the carriages, anA endless chain mounted to travel about each of Vthe tracks and connected to the carriage on the track, a differential associated With each of the endless chains', means for .actuating the chains through the differentials, revoluble means at the front of the frame, motiontransmission means from the revoluble means at the front to the differentials, and means from the shoes to the revoluble means for operating the said revoluble means.

7 A tractor comprising a frame, Wheels supporting the front of the frame, shoes for the rear of the frame, a carriage associated With each shoe, an endless track for each of the carriages, an endless chain revolubly mounted about the track and connected to the carriage on the track so that the carriage is constrained to move With the chaina differential associated vwith each chain, means for actuating lthe chainsthrough the differ-E entials, a rack associated with each of the shoes, a pinion for each rack, a shaft lfor each pinion constrained to `rotate therewith, and motion-transmission means from Yeach of the shafts to the diiferential associated Y EDWARD E. LARSON.. 

